1. Field of the Invention
The present invention relates to a developing device mounted in an image forming apparatus, such as a copying machine or a printer.
2. Related Art
When it has been used for a long period of time, an electrophotographic image forming apparatus requires adjusting, cleaning, and replacing operations. For example, it is necessary to replace the photosensitive drum, supply and replace the developer, and adjust, clean, and replace other components (such as the charger and the cleaner container). For a person other than a serviceperson with expertise, it has been virtually impossible to perform such maintenance operations.
In view of this, an image forming apparatus based on the electrophotographic image forming process adopts a process cartridge system, in which the electrophotographic photosensitive body and the process means acting thereon are integrated into a cartridge that is detachably attachable to the main body of the image forming apparatus. With this process cartridge system, the user can perform the maintenance of the apparatus by himself or herself without having to rely on a serviceperson, thus achieving a substantial improvement in terms of operability. That is why the process cartridge system is widely used in the field of image forming apparatuses.
FIG. 12 shows a conventional developing unit. A conventional developer unit 45 is formed by joining, by ultrasonic welding, a developing frame 43 supporting a developing member, such as a developing roller 48, with a toner containing frame body consisting of a toner container 46 in which agitating members 49 and a toner regulating plate 47 are provided and with which a toner container cover 44 is joined by ultrasonic welding.
In electrophotographic image forming apparatuses including such a process cartridge, there is a tendency toward an increase in the volume of the toner container and an increase in the size of the container for waste toner so that the service life of the process cartridge until its replacement may be prolonged.
However, when the volume of the toner container is increased, the weight of the toner increases. When the amount of developer is increased in the conventional image forming apparatus, the process cartridge may be dropped due to the weight of the toner, with the result that the toner sealing member is damaged to allow toner to leak. To avoid this, a toner regulating plate or the like, which is a separate component, has conventionally been provided in the toner container when forming the frame body.
However, this system has a problem in that it requires a separate component, resulting in high cost. Moreover, when the toner container cover is joined by ultrasonic welding, oscillatory welding or the like, with the toner regulating plate being mounted in the toner container, there is a danger that waste resin may be generated where the toner regulating plate and the toner container are in contact with each other and where the toner regulating plate and the toner container cover are in contact with each other, resulting in image disturbance.
The present invention has been made in view of the above problem. It is an object of the present invention to provide an inexpensive developing device.
Another object of the present invention is to provide a developing device which does not easily allow intrusion of impurities into the developer container at the time of production.
Still another object of the present invention is to provide a developing device comprising: a developer bearing member; and a developer container for containing a developer, the developer container including a developer containing portion, a partition member dividing an interior of the developer containing portion into a plurality of rooms, and a cover for covering the developer containing portion, wherein the partition member is molded integrally with the cover.
Other objects of the present invention will become apparent from the following detailed description with reference to the accompanying drawings.